Our Safari Books Online database has travel guides for 16 major cities, including New York City, Washington, Chicago, Berlin, and Hong Kong (but not Charlotte, Dublin, or Shanghai).  If you're standing on a street corner in Barcelona, you can access the Spain guide and search on Barcelona.  Nice maps  and you won't entirely look like a tourist. (There are also lots of books on photography.)

USA and Canada:  Washington, New York City, Boston, Chicago, San Francisco, Seattle, Toronto

Europe:  London, Paris, Rome, Madrid, Barcelona, Berlin, Munich

Asia: Beijing, Hong Kong,